Considering the cross-exchange capacity of electric power and energy and the regulation of side electricity, an optimization model for electric power and energy balance analysis is proposed to minimize the cost of adjustment measures. Taking into account the impact of reservoir operation plan and maintenance plan for the unit generating capacity, reservoir operation and unit maintenance-related constraints are constructed in the model, such that the power consumption analysis results are more reasonable. In order to deal with randomness of the load, runoff, and wind power appropriately, electric power constraint, energy constraint and water balance constraint are expressed in the form of probability based on chance-constrained programming. Then in the solution process, the stochastic model is transferred to the determined model. Simulation results of actual systems verify the rationality and efficiency of the proposed method.